As a conventional working apparatus of this kind, there is one as shown in FIG. 10.
The conventional apparatus relates to an automatic part mounting apparatus which picks up by a work head 51 an electronic part disposed on a part feed unit 50 and transports it into a work on a working line 52. More especially onto a substrate 53, thereby mounting the electronic part in a predetermined position on the substrate 53. The work head 51 moves in two horizontal directions X and Y to enable it to mount the electronic part on the substrate 53.
Further, the subtrate 53 is constructed so as to be positioned by a positioning means 55 in a predetermined stopped position at a work station 54 on the working line 52 to thereby be subjected to the mounting operation. The substrate 53 on which a necessary number of electronic parts are mounted is then moved on to a discharge position 56. Almost at the same time, the next substrate 53 at a stand-by position 57 is transported to the work station 54 and an electronic part is mounted similarly on the substrate 53. In addition, reference numeral 58 designates a stopper for stopping the next substrate 53 in the stand-by position 57.
The aforesaid conventional apparatus takes a relatively long loading time to move the substrate 53 on which the mounting operation has been completed from the work station 54 and to move a new substrate 53 thereto, e.g. such as several seconds to about 5 seconds.
Accordingly, when the number of parts to be mounted on one substrate is small, a loss in the loading time seriously affects work efficiency and decreases it considerably.
In the graph in FIG. 9 the abscissa represents the number of parts mounted on one substrate and the ordinate represents the number of parts mounted in 400 minutes of operating time. The solid line shows the work efficiency of the conventional apparatus while the dot-dash line shows the work efficiency of apparatus embodying this invention. The aforesaid problem can be apparently seen from this graph.